Effective selection of a virtual machine to be moved outside influence range of a failure

ABSTRACT

A method performed by an apparatus is provided. The apparatus extracts a virtual machine before starting operation from among virtual machines within a range of influence of a failure upon detection of the failure. With reference to a storage unit storing history information concerning operation of a virtual machine, the apparatus generates first information corresponding to time intervals of operation start time of the extracted virtual machine, second information corresponding to movement required time required to move the extracted virtual machine out of the range of influence of the failure, and third information corresponding to recovery required time required for recovery of the failure detected to have occurred. The apparatus determines whether to move the extracted virtual machine out of the range of influence of the failure, based on the generated first, second, and third information.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of theprior Japanese Patent Application No. 2018-113809, filed on Jun. 14,2018, the entire contents of which are incorporated herein by reference.

FIELD

The embodiment discussed herein is related to effective selection of avirtual machine to be moved outside influence range of a failure.

BACKGROUND

For example, an operator providing services to a user (hereinaftersimply referred to as the operator) builds and operates an informationprocessing system for providing the services. For example, the operatoruses a plurality of virtual machines operated in a physical machine, forexample, to build the information processing system.

Upon occurrence of a failure likely to affect the services provided tothe user, for example, the operator estimates the cause of the failureand the range of influence thereof. Thereafter, the operator takesmeasures corresponding to the estimated cause and range of influence ofthe failure (see, for example, Japanese Laid-open Patent Publication No.11-259331).

SUMMARY

According to an aspect of the embodiments, a method performed by anapparatus is provided. The apparatus extracts a virtual machine beforestarting operation from among virtual machines within a range ofinfluence of a failure upon detection of the failure. With reference toa storage unit storing history information concerning operation of avirtual machine, the apparatus generates first information correspondingto time intervals of operation start time of the extracted virtualmachine, second information corresponding to movement required timerequired to move the extracted virtual machine out of the range ofinfluence of the failure, and third information corresponding torecovery required time required for recovery of the failure detected tohave occurred. The apparatus determines whether to move the extractedvirtual machine out of the range of influence of the failure, based onthe generated first, second, and third information.

The object and advantages of the invention will be realized and attainedby means of the elements and combinations particularly pointed out inthe claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration of an informationprocessing system;

FIG. 2 is a diagram illustrating a hardware configuration of aninformation processor;

FIG. 3 is a functional block diagram of the information processor;

FIG. 4 is a flowchart explaining an outline of failure handlingprocessing according to an embodiment;

FIG. 5 is a diagram explaining the outline of the failure handlingprocessing according to an embodiment;

FIG. 6 is a diagram explaining the outline of the failure handlingprocessing according to an embodiment;

FIG. 7 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 8 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 9 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 10 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 11 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 12 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 13 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 14 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 15 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 16 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 17 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 18 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIG. 19 is a flowchart explaining details of the failure handlingprocessing according to an embodiment;

FIGS. 20A to 20D are diagrams explaining examples of historyinformation;

FIGS. 21A to 21D are diagrams explaining examples of operation intervalinformation, movement time information, recovery time information, andaddition time information;

FIGS. 22A to 22D are diagrams explaining examples of graphs illustratingthe operation interval information, the movement time information, therecovery time information, and the addition time information;

FIG. 23 is a diagram explaining an example of post-conversion operationinterval information;

FIG. 24 is a diagram explaining an example of a graph illustrating thepost-conversion operation interval information;

FIG. 25 is a diagram explaining an example of post-conversion recoverytime information;

FIG. 26 is a diagram explaining an example of a graph illustrating thepost-conversion recovery time information;

FIGS. 27A and 27B are diagrams explaining examples of a firstprobability and a second probability;

FIG. 28 is a diagram explaining an example of importance information andpriority information; and

FIG. 29 is a diagram explaining an example of the importance informationand the priority information.

DESCRIPTION OF EMBODIMENTS

Measures, which are to be taken by the operator upon occurrence of afailure likely to affect the services provided to the user, includesmoving the virtual machine to a safe physical machine outside the rangeof influence of the failure.

For example, when there is a virtual machine not subjected to anyprocessing (hereinafter also referred to as the virtual machine not inoperation) within the range of influence of the failure, the operatormay estimate that the virtual machine is one that is not yet affected bythe failure. Therefore, in this case, the operator may suppress theinfluence of the failure that has occurred by moving the virtual machinenot in operation to the safe physical machine before the virtual machinestarts its operation.

It is desirable to take into consideration the time when the virtualmachine not in operation starts its operation (hereinafter also referredto as the operation start time), the time required to move the virtualmachine not in operation (hereinafter also referred to as the movementrequired time), and the like to determine whether or not the virtualmachine not in operation may be moved.

However, the operation start time and movement required time for thevirtual machine vary according to the usage of the services by the user,or the like. Therefore, the operator may sometimes not easily determinethe virtual machine to be moved in the event of failure.

It is preferable to enable the operator to determine a virtual machineto be moved in the event of failure.

[Configuration of Information Processing System]

FIG. 1 is a diagram illustrating a configuration of an informationprocessing system 10. The information processing system 10 illustratedin FIG. 1 includes an information processor 1, an information storagearea 130, physical machines 2 a, 2 b, and 2 c, and an operation terminal5. The information storage area 130 is a storage area included in astorage device (not illustrated) located outside the informationprocessor 1, or a storage area located inside the information processor1.

Hereinafter, operation means that some kind of processing goes underway,for example, that processing load is increased with the start ofprocessing such as batch processing.

The physical machine 2 a is a physical machine in which a plurality ofvirtual machines including virtual machines 3 a and 3 b are operated.Likewise, the physical machine 2 b is a physical machine in which aplurality of virtual machines including virtual machines 3 c and 3 d areoperated, and the physical machine 2 c is a physical machine in which aplurality of virtual machines including virtual machines 3 e and 3 f areoperated. Hereinafter, the physical machines 2 a to 2 c are alsocollectively referred to as the physical machine 2 which means any oneof the physical machines 2 a to 2 c. Likewise, hereinafter, theplurality of virtual machines including the virtual machines 3 a to 3 fare also collectively referred to as the virtual machine 3 which meansany one of the virtual machines 3 a to 3 f.

The operation terminal 5 is, for example, a personal computer (PC) usedby an operator. For example, the operation terminal 5 transmitsinformation inputted by the operator to the information processor 1.

The information processor 1 regularly monitors, for example, operatingconditions of each physical machine 2 or a network (not illustrated).Upon detection of occurrence of a failure that affects the operation ofthe virtual machine 3, the information processor 1 takes measures tomove the virtual machine 3 currently not in operation (virtual machine 3to be operated in the future), among the virtual machines 3 within therange of influence of the failure that has occurred, to the physicalmachine 2 outside the range of influence of the failure.

For example, the information processor 1 refers, in this case, to theinformation storage area 130 storing history information 131 including,for example, operation start time of each virtual machine 3 in the past,movement required time required for the virtual machine 3 to move in thepast between the physical machines 2, and the like. The informationprocessor 1 moves the virtual machine 3 movable to the physical machine2 outside the range of influence of the failure (hereinafter alsoreferred to as the different physical machine 2) before the nextoperation is started, among the virtual machines 3 within the range ofinfluence of the failure that has occurred and currently not inoperation.

However, the operation start time and the movement required time for thevirtual machine 3 vary according to the usage of services by a user, andthe like. Therefore, the operator may sometimes not easily determine thevirtual machine 3 to be moved in the event of occurrence of a failure.

Upon detection of occurrence of a failure, the information processor 1according to this embodiment extracts the virtual machine 3 beforestarting its operation from among the virtual machines 3 within therange of influence of the failure detected to have occurred. Theinformation processor 1 refers to the information storage area 130storing the history information 131 to generate informationcorresponding to time intervals of the operation start time of theextracted virtual machine 3 (hereinafter also referred to as theoperation interval information or first information), informationcorresponding to the movement required time required to move theextracted virtual machine 3 to the different physical machine 2(hereinafter also referred to as the movement time information or secondinformation), and information corresponding to recovery required timerequired for recovery of the failure detected to have occurred(hereinafter also referred to as the recovery time information or thirdinformation).

The information processor 1 determines whether to move the extractedvirtual machine 3 to the different physical machine 2, based on thegenerated operation interval information, movement time information, andrecovery time information.

For example, the information processor 1 refers to the historyinformation 131 that is the information about failures that haveoccurred in the past and the information about the operating conditionsof the virtual machine 3 to predict the time when the extracted virtualmachine 3 starts its next operation, the time required when theextracted virtual machine 3 is to be moved, and the time required forrecovery of the failure detected to have occurred. The informationprocessor 1 specifies the virtual machine 3 that may be successfullymoved to the different physical machine 2 before the next operation isstarted, based on the various kinds of information predicted. Theinformation processor 1 further determines the specified virtual machine3 to be a virtual machine 3 to be moved to the different physicalmachine 2.

Thus, the information processor 1 may properly specify the virtualmachine 3 required to be moved to the different physical machine 2 inthe event of a failure. Therefore, the operator may further suppress theinfluence of the failure that has occurred.

[Hardware Configuration of Information Processing System]

Next, a hardware configuration of the information processing system 10is described. FIG. 2 is a diagram illustrating a hardware configurationof the information processor 1.

The information processor 1 includes a central processing unit (CPU) 101that is a processor, a memory 102, an external interface (I/O unit) 103,and a storage medium 104. The respective components are connected toeach other through a bus 105.

The storage medium 104 includes, for example, a program storage area(not illustrated) to store a program 110 for performing processing ofdetermining the virtual machine 3 to be moved to the different physicalmachine 2 in the event of a failure (hereinafter also referred to as thefailure handling processing). The storage medium 104 also includes, forexample, an information storage area 130 (hereinafter also referred toas the storage unit 130) to store information for use in the failurehandling processing. The storage medium 104 may be, for example, a harddisk drive (HDD).

The CPU 101 performs the failure handling processing by executing theprogram 110 loaded into the memory 102 from the storage medium 104.

The external interface 103 performs communication with the physicalmachine 2, for example.

[Functions of Information Processing System]

Next, description is given of functions of the information processingsystem 10. FIG. 3 is a functional block diagram of the informationprocessor 1 with reference to FIG. 2.

The information processor 1 realizes various functions including aninformation management unit 111, a failure detection unit 112, a VMextraction unit 113, an information generation unit 114, and a movementdetermination unit 115, through organic cooperation between thehardware, such as the CPU 101 and the memory 102, and the program 110.

As illustrated in FIG. 3, the information processor 1 stores the historyinformation 131, operation interval information 132, movement timeinformation 133, recovery time information 134, addition timeinformation 135, importance information 136, and priority information137 in the information storage area 130.

The information management unit 111 generates the history information131 to store in the information storage area 130. The historyinformation 131 is, for example, information including the operationstart time and the movement required time in the past for each virtualmachine 3. The history information 131 is also, for example, informationincluding the time required for recovery of a failure that has occurredin the past (hereinafter also referred to as the recovery required time)and predicted time for the recovery required time, which is predictedbased upon the past occurrence of failure. A example of the historyinformation 131 is described later.

The failure detection unit 112 detects occurrence of a failure thataffects operations of the virtual machine 3. For example, the failuredetection unit 112 regularly monitors states of the physical machine 2,a network, and the like. When the state of the physical machine 2 or thelike becomes a predetermined state, the failure detection unit 112determines that a failure has occurred, the failure having contentscorresponding to the predetermined state.

Upon detection of the occurrence of the failure by the failure detectionunit 112, the VM extraction unit 113 extracts the virtual machine 3before starting its operation from among the virtual machines 3 withinthe range of influence of the failure. For example, the VM extractionunit 113 may refer to an operation schedule (not illustrated) for thevirtual machine 3 stored in the information storage area 130, forexample, to extract the virtual machine 3 scheduled to start itsoperation in the future from among the virtual machines 3 within therange of influence of the failure and currently not in operation.

The information generation unit 114 refers to the history information131 stored in the information storage area 130 to generate the operationinterval information 132 corresponding to time intervals of theoperation start time for the virtual machine 3 extracted by the VMextraction unit 113. For example, the information generation unit 114refers to the history information 131 stored in the information storagearea 130 to specify the time intervals of the operation start time inthe past for the virtual machine 3 extracted by the VM extraction unit113. The information generation unit 114 generates informationindicating a percentage for the same time interval (for example, thesame time interval zone) as the operation interval information 132, foreach of the specified time intervals of the operation start time.

The information generation unit 114 also refers to the historyinformation 131 stored in the information storage area 130 to generatethe movement time information 133 corresponding to the movement requiredtime required to move the virtual machine 3 extracted by the VMextraction unit 113 to the different physical machine 2. For example,the information generation unit 114 refers to the history information131 stored in the information storage area 130 to specify the movementrequired time in the past for the virtual machine 3 extracted by the VMextraction unit 113. The information generation unit 114 generatesinformation indicating a percentage for the same movement required time(for example, the same movement required time zone) as the movement timeinformation 133, for each of the specified movement required times.

The information generation unit 114 further generates the recovery timeinformation 134 corresponding to the recovery required time required forrecovery of the failure detected to have occurred by the failuredetection unit 112. For example, the information generation unit 114refers to the history information 131 stored in the information storagearea 130 to calculate a time difference between the recovery requiredtime upon the past occurrence of the failure detected by the failuredetection unit 112 and the predicted time for the recovery requiredtime, which is predicted based upon the past occurrence of the failure.The information generation unit 114 generates information indicating apercentage for the same time difference (for example, time differencezone) as the recovery time information 134, for each of the calculatedtime differences.

The movement determination unit 115 determines whether to move thevirtual machine 3 extracted by the VM extraction unit 113 to thedifferent physical machine 2, based on the operation intervalinformation 132, the movement time information 133, and the recoverytime information 134 generated by the information generation unit 114.The addition time information 135, the importance information 136, andthe priority information 137 are described later.

Outline of First Embodiment

Next, an outline of a first embodiment is described. FIG. 4 is aflowchart explaining an outline of failure handling processing accordingto the first embodiment. FIGS. 5 and 6 are diagrams explaining theoutline of the failure handling processing according to the firstembodiment.

As illustrated in FIG. 4, the information processor 1 waits untiloccurrence of a failure is detected (NO in S1). For example, theinformation processor 1 detects a failure occurring in each physicalmachine 2 or each virtual machine 3 by detecting output of an error fromeach physical machine 2 or each virtual machine 3.

When occurrence of a failure is detected (YES in S1), the informationprocessor 1 extracts the virtual machine 3 before starting its operationfrom among the virtual machines 3 within the range of influence of thefailure detected to have occurred (S2).

For example, the information processor 1 specifies a virtual machine 3within the range of influence of the failure detected to have occurredin S1 and currently not in operation, from among a plurality of virtualmachines 3 including virtual machines 3 a and 3 b operated in a physicalmachine 2 a, a plurality of virtual machines 3 including virtualmachines 3 c and 3 d operated in a physical machine 2 b, and a pluralityof virtual machines 3 including virtual machines 3 e and 3 f operated ina physical machine 2 c, as illustrated in FIG. 5.

The information processor 1 refers to the information storage area 130storing the history information 131 to generate operation intervalinformation 132 corresponding to time intervals of the operation starttime of the virtual machine 3 extracted in S2 (S3). The informationprocessor 1 also refers to the information storage area 130 storing thehistory information 131 to generate movement time information 133corresponding to movement required time required to move the virtualmachine 3 extracted in S2 to a different physical machine 2 (S4). Theinformation processor 1 further refers to the information storage area130 storing the history information 131 to generate recovery timeinformation 134 corresponding to recovery required time required forrecovery of the failure detected to have occurred in S1 (S5).

The information processor 1 determines whether to move the virtualmachine 3 extracted in S2 to the different physical machine 2, based onthe operation interval information 132 generated in S3, the movementtime information 133 generated in S4, and the recovery time information134 generated in S5 (S6).

For example, the information processor 1 stores the generated operationinterval information 132, movement time information 133, and recoverytime information 134 in the information storage area 130, as illustratedin FIG. 6. When the virtual machines 3 a and 3 b are specified in S2,for example, the information processor 1 refers to the operationinterval information 132, the movement time information 133, and therecovery time information 134 stored in the information storage area 130to determine whether to move the virtual machines 3 a and 3 b to anotherphysical machine 2 (physical machine 2 other than the physical machine 2a).

Thus, the information processor 1 may properly specify the virtualmachine 3 required to be moved to the different physical machine 2 inthe event of a failure. As a result, the operator may further suppressthe influence of the failure that has occurred.

Details of First Embodiment

Next, description is given of details of the first embodiment. FIGS. 7to 19 are flowcharts explaining details of failure handling processingaccording to the first embodiment. FIGS. 20 to 29 are diagramsexplaining the details of the failure handling processing according tothe first embodiment.

[History Information Accumulation Processing]

First, description is given of processing of accumulating the historyinformation 131 (hereinafter also referred to as the history informationaccumulation processing) in the failure handling processing.

As illustrated in FIG. 7, the information management unit 111 in theinformation processor 1 waits until it is detected that the virtualmachine 3 operated in the physical machine 2 has started its operation(NO in S201). For example, the information management unit 111 acquiresCPU utilization of the virtual machine 3 operated in each physicalmachine 2 from each physical machine 2 or each virtual machine 3, anddetects the start of the operation of each virtual machine 3 based on achange in CPU utilization for each virtual machine 3.

When it is detected that the virtual machine 3 has started its operation(YES in S201), the information management unit 111 specifies theoperation start time of the virtual machine 3 detected to have startedits operation (S202).

The information management unit 111 stores the operation start timespecified in S202 as a part of the history information 131 (hereinafteralso referred to as first history information 131 a) in the informationstorage area 130 (S203).

As illustrated in FIG. 8, the information management unit 111 waitsuntil it is detected that the movement of the virtual machine 3 to thedifferent physical machine 2 is completed (NO in S211). For example, theinformation management unit 111 waits until it is detected that livemigration of the virtual machine 3 to the different physical machine 2is completed.

When it is detected that the movement of the virtual machine 3 iscompleted (YES in S211), the information management unit 111 specifiesmovement required time required to move the virtual machine 3 detectedto have completed its movement (S212). For example, the informationmanagement unit 111 detects not only the completion of the movement ofthe virtual machine 3 to the different physical machine 2 but also thestart of movement of the virtual machine 3 to the different physicalmachine 2, and specifies the time from the start of movement to thecompletion of movement as the movement required time.

When the movement of the virtual machine 3 from one physical machine 2to another physical machine 2 is started, each physical machine 2 maytransmit information indicating the start of movement of the virtualmachine 3 to the information processor 1. Likewise, when the movement ofthe virtual machine 3 from one physical machine 2 to another physicalmachine 2 is completed, each physical machine 2 may transmit informationindicating the completion of movement of the virtual machine 3 to theinformation processor 1. The information management unit 111 may specifythe movement required time by referring to the information transmittedfrom the physical machine 2.

The information management unit 111 stores the movement required timespecified in S212 as a part of the history information 131 (hereinafteralso referred to as second history information 131 b) in the informationstorage area 130 (S213).

As illustrated in FIG. 9, the failure detection unit 112 in theinformation processor 1 waits until occurrence of a failure that affectsthe virtual machine 3 operated in the physical machine is detected (NOin S221). For example, the failure detection unit 112 detects theoccurrence of the failure that affects each virtual machine 3 bydetecting error information outputted from each physical machine 2 oreach virtual machine 3.

When the occurrence of the failure is detected (YES in S221), theinformation management unit 111 waits until a predicted time forrecovery required time for the failure that has occurred is inputted bythe operator (NO in S222). For example, the information management unit111 waits until the predicted time for the recovery required time forthe failure that has occurred is inputted through the operation terminal5.

When it is detected that the predicted time for the recovery requiredtime for the failure that has occurred is inputted by the operator (YESin S222), the failure detection unit 112 waits until recovery of thefailure that has occurred is detected (NO in S223). For example, thefailure detection unit 112 waits until information indicating that thefailure has been recovered is inputted by the operator.

When the recovery of the failure that has occurred is detected (YES inS223), the information management unit 111 calculates the recoveryrequired time required for recovery of the failure detected to haveoccurred in S221, from the time when the occurrence of the failure isdetected in S221 and the time when the recovery of the failure isdetected in S223 (S224). For example, the information management unit111 calculates the time from the time when the occurrence of the failureis detected in S221 to the time when the recovery of the failure isdetected in S223, as the recovery required time.

The information management unit 111 stores the recovery required timecalculated in S224 and the predicted time for the recovery required timedetected to have been inputted in S222 as a part of the historyinformation 131 (hereinafter also referred to as third historyinformation 131 c) in the information storage area 130 (S225).

As illustrated in FIG. 10, the information management unit 111 furtherwaits, for example, until addition of physical resources is detected(S231). For example, the information management unit 111 waits untilinformation indicating completion of the addition of physical resourcesis inputted by the operator.

For example, when all the virtual machines 3 affected by the failurethat has occurred may not be moved to the different physical machine 2,the operator suppresses the influence of the failure that has occurred,for example, by adding physical resources.

Such addition of the physical resources includes, for example, addinghardware to the physical machine 2, adding and switching a network forconnection with the physical machine 2, adding a storage deviceaccessible to the physical machine 2, changing settings for a datastorage destination, and the like.

When the addition of the physical resources is detected (YES in S231),the information management unit 111 specifies addition required timerequired for the addition of the physical resources detected to be added(S232). For example, as the addition required time, the informationmanagement unit 111 specifies, for example, the time inputted by theoperator as the time required for the addition of the physicalresources.

The information management unit 111 stores the addition required timespecified in S232 as a part of the history information 131 (hereinafteralso referred to as fourth history information 131 d) in the informationstorage area 130 (S233). A example of the history information 131 isdescribed below.

[Example of History Information]

FIGS. 20A to 20D are diagrams explaining examples of the historyinformation 131. For example, FIG. 20A is a diagram explaining a exampleof the first history information 131 a, FIG. 20B is a diagram explaininga example of the second history information 131 b, FIG. 20C is a diagramexplaining a example of the third history information 131 c, and FIG.20D is a diagram explaining a example of the fourth history information131 d. The following description is given assuming that the first tofourth history information 131 a to 131 d are generated for each virtualmachine 3 and for each physical machine 2 in which the virtual machine 3is operated. The following description is also given assuming that FIGS.20A to 20D are diagrams illustrating the first to fourth historyinformation 131 a to 131 d, respectively, which are stored when onevirtual machine 3 is operated in the physical machine 2 a described withreference to FIG. 1 and the like.

The first history information 131 a and the second history information131 b may be generated, for example, for each virtual machine 3, foreach physical machine 2 in which the virtual machine 3 is operated, andfor the number of the virtual machines 3 operated in the physicalmachine 2. The second history information 131 b may be generated, forexample, for each virtual machine 3, for each physical machine 2 inwhich the virtual machine 3 is operated, for the number of the virtualmachines 3 operated in the physical machine 2, and also for each pieceof environmental information such as CPU utilization and memory usageupon starting movement between the physical machines 2.

The third history information 131 c may be generated, for example, forthe number of the virtual machines 3 operated in the physical machine 2.The fourth history information 131 d may be generated, for example, foreach physical machine 2 in which the virtual machine 3 is operated.

[Example of First History Information]

First, a example of the first history information 131 a is described.

The first history information 131 a illustrated in FIG. 20A includesitems of “item number” for identifying each information included in thefirst history information 131 a, “operation start time” for storing theoperation start time specified in S202, and “time interval” for storingthe time interval of the consecutive times stored in “operation starttime”.

In the first history information 131 a illustrated in FIG. 20A, forexample, “12:05” is stored as “operation start time” in the informationwith “item number” of “1”. In the first history information 131 aillustrated in FIG. 20A, “-” indicating that no information is stored as“time interval” is stored in the information with “item number” of “1”.

In the first history information 131 a illustrated in FIG. 20A, “15:00”is stored as “operation start time” in the information with “itemnumber” of “2”. In the first history information 131 a illustrated inFIG. 20A, information with “item number” of “2” includes “2:55” storedas “time interval”, which is the time interval between the times “12:05”and “15:00” stored in “operation start time” for the information with“item number” of “1” and “2”. As for the other information included inFIG. 20A, description thereof is omitted.

[Example of Second History Information]

Next, a example of the second history information 131 b is described.

The second history information 131 b illustrated in FIG. 20B includesitems of “item number” for identifying each information included in thesecond history information 131 b and “movement required time” forstoring the movement required time specified in S212.

In the second history information 131 b illustrated in FIG. 20B, forexample, “2:10” is stored as “movement required time” in the informationwith “item number” of “1”. In the second history information 131 billustrated in FIG. 20B, “1:40” is stored as “movement required time” inthe information with “item number” of “2”. As for the other informationincluded in FIG. 20B, description thereof is omitted.

[Example of Third History Information]

Next, a example of the third history information 131 c is described.

The third history information 131 c illustrated in FIG. 20C includesitems of “item number” for identifying each information included in thethird history information 131 c, “recovery required time” for storingthe recovery required time calculated in S224, and “predicted time” forstoring the predicted time for the recovery required time detected tohave been inputted in S222. The third history information 131 cillustrated in FIG. 20C also includes an item of “time difference” forstoring a time difference calculated by subtracting the time stored in“predicted time” from the time stored in “recovery required time”.

In the third history information 131 c illustrated in FIG. 20C, forexample, the information with “item number” of “1” includes “4:30”stored as “recovery required time”, “4:00” stored as “predicted time”,and “+0:30” stored as “time difference”.

In the third history information 131 c illustrated in FIG. 20C, forexample, the information with “item number” of “2” includes “1:15”stored as “recovery required time”, “2:00” stored as “predicted time”,and “−0:45” stored as “time difference”. As for the other informationincluded in FIG. 20C, description thereof is omitted.

The third history information 131 c may be generated, for example,according to type of the failure that has occurred. Alternatively, thethird history information 131 c may be generated, for example, accordingto person in charge of dealing with the failure that has occurred.

[Example of Fourth History Information]

Next, a example of the fourth history information 131 d is described.

The fourth history information 131 d illustrated in FIG. 20D includesitems of “item number” for identifying each information included in thefourth history information 131 d and “addition required time” forstoring the addition required time specified in S232.

In the fourth history information 131 d illustrated in FIG. 20D, forexample, “0:10” is stored as “addition required time” in the informationwith “item number” of “1”. In the fourth history information 131 dillustrated in FIG. 20D, “0:10” is stored as “addition required time” inthe information with “item number” of “2”. As for the other informationincluded in FIG. 20D, description thereof is omitted.

The fourth history information 131 d may be generated, for example,according to type of the physical resources added. Alternatively, thefourth history information 131 d may be generated, for example,according to size of the physical resources added.

[VM Movement Determination Processing]

Next, description is given of processing of specifying the virtualmachine 3 to be moved to the different physical machine 2 (hereinafteralso referred to as the VM movement determination processing) in thefailure handling processing.

As illustrated in FIG. 11, the failure detection unit 112 waits untiloccurrence of a failure is detected (NO in S11). When the occurrence ofthe failure is detected (YES in S11), the VM extraction unit 113 in theinformation processor 1 extracts the virtual machine 3 before startingits operation from among the virtual machines 3 within the range ofinfluence of the failure detected to have occurred (S12).

The VM extraction unit 113 specifies one of the virtual machines 3extracted in S12 (S13).

The information generation unit 114 in the information processor 1refers to the information storage area 130 storing the first historyinformation 131 a to specify the time interval between the operationstart times in the past for the virtual machine 3 specified in S13(S14).

For example, the information generation unit 114 specifies the physicalmachine 2 in which the virtual machine 3 specified in S13 is operated.The information generation unit 114 refers to the informationcorresponding to the specified physical machine 2 and to the virtualmachine 3 specified in S13, among the first history information 131 a,for example, to specify the time interval between the operation starttimes in the past for the virtual machine 3 specified in S13.

The information generation unit 114 further generates operation intervalinformation 132 indicating the percentage for the same time intervalzone of the time interval specified in S14 (S15). A example of theoperation interval information 132 is described below.

[Example of Operation Interval Information]

FIGS. 21A to 21D are diagrams explaining examples of the operationinterval information 132, the movement time information 133, therecovery time information 134, and the addition time information 135.For example, FIG. 21A is a diagram explaining a example of the operationinterval information 132.

The operation interval information 132 illustrated in FIG. 21A includesitems of “item number” for identifying each information included in theoperation interval information 132, “time interval zone” for storing therange of time intervals, and “percentage” for storing the percentage ofthe information stored in “time interval zone” in the whole information.

In the operation interval information 132 illustrated in FIG. 21A, forexample, the information with “item number” of “1” includes “2:45 to3:00” stored as “time interval zone” and “10(%)” stored as “percentage”.In the operation interval information 132 illustrated in FIG. 21A, theinformation with “item number” of “2” includes “3:00 to 3:15” stored as“time interval zone” and “15(%)” stored as “percentage”. As for theother information included in FIG. 21A, description thereof is omitted.

Referring back to FIG. 11, the information generation unit 114 specifiesa median value of the time interval zone corresponding to the highestpercentage among percentage of the information included in the operationinterval information 132 generated in S15 (S16). A example of theprocessing in S16 is described below.

[Example of Processing in S16]

FIGS. 22A to 22D are diagrams explaining examples of graphs illustratingthe operation interval information 132, the movement time information133, the recovery time information 134, and the addition timeinformation 135 illustrated in FIGS. 21A to 21D. For example, FIG. 22Ais a diagram explaining a example of the graph illustrating theoperation interval information 132. The horizontal axis and the verticalaxis in each of the graphs illustrated in FIGS. 22A to 22D correspond totime and percentage, respectively.

In the operation interval information 132 illustrated in FIG. 21A, thetime interval zone corresponding to the highest percentage (timeinterval zone) is “3:15 to 3:30”. Therefore, in this case, asillustrated in FIG. 22A, the information generation unit 114 specifies 3hours 22 minutes 30 seconds, which is the median value between 3 hours15 minutes and 3 hours 30 minutes, as the median value of the timeinterval zone corresponding to the highest percentage, among thepercentage information included in the operation interval information132 generated in S15.

In S16, the information generation unit 114 may calculate theperiodicity by performing autocorrelation analysis using resourceinformation (for example, CPU utilization of each physical machine 2,and the like) acquired from each physical machine 2 or each virtualmachine 3, instead of using the time interval zone included in the firsthistory information 131 a described with reference to FIG. 20A, forexample, and specify the median value of the time interval zone from thecalculated periodicity.

Referring to FIG. 12, the information generation unit 114 refers to theinformation storage area 130 storing the second history information 131b to specify the movement required time of the virtual machine 3 in thepast specified in S13 (S21).

For example, the information generation unit 114 specifies the physicalmachine 2 in which the virtual machine 3 specified in S13 is operated.The information generation unit 114 refers to the informationcorresponding to the specified physical machine 2 and the virtualmachine 3 specified in S13, among the second history information 131 b,for example, to specify the movement required time of the virtualmachine 3 in the past specified in S13.

The information generation unit 114 generates information indicating thepercentage for the same time zone of the movement required timespecified in S21, as the movement time information 133 (S22). A exampleof the movement time information 133 is described below.

[Example of Movement Time Information]

FIG. 21B is a diagram explaining a example of the movement timeinformation 133.

The movement time information 133 illustrated in FIG. 21B includes itemsof “item number” for identifying each information included in themovement time information 133, “movement required time zone” for storingthe range of movement required times, and “percentage” for storing thepercentage of the information stored in “movement required time zone” inthe whole information.

In the movement time information 133 illustrated in FIG. 21B, forexample, the information with “item number” of “1” includes “0:30 to1:00” stored as “movement required time zone” and “6(%)” stored as“percentage”. In the movement time information 133 illustrated in FIG.21B, the information with “item number” of “2” includes “1:00 to 1:30”stored as “movement required time zone” and “11(%)” stored as“percentage”. As for the other information included in FIG. 21B,description thereof is omitted.

Referring back to FIG. 12, the information generation unit 114 specifiesa median value of the time zone corresponding to the highest percentageamong the percentage of the information included in the movement timeinformation 133 generated in S22, as a second reference time (S23). Aexample of the processing in S23 is described below.

[Example of Processing in S23]

FIG. 22B is a diagram explaining a example of the graph illustrating themovement time information 133.

In the movement time information 133 illustrated in FIG. 21B, the timezone corresponding to the highest percentage (movement required timezone) is “2:00 to 2:30”. Therefore, in this case, the informationgeneration unit 114 specifies 2 hours 15 minutes, which is the medianvalue between 2 hours and 2 hours 30 minutes, as a second referencetime, as illustrated in FIG. 22B.

Referring back to FIG. 12, the information generation unit 114 refers tothe information storage area 130 storing the third history information131 c to specify a time difference between the recovery required timeupon past occurrence of the failure detected to have occurred in S11 andthe predicted time for the recovery required time predicted upon pastoccurrence of the failure that has occurred in S11 (S24).

For example, the information generation unit 114 specifies the physicalmachine 2 in which the virtual machine 3 specified in S13 is operated.The information generation unit 114 refers to the informationcorresponding to the specified physical machine 2 and the virtualmachine 3 specified in S13, among the third history information 131 c,and specifies a time difference between the recovery required time uponpast occurrence of the failure detected to have occurred in S11 and thepredicted time for the recovery required time predicted upon pastoccurrence of the failure that has occurred in S11.

The information generation unit 114 generates recovery time information134 indicating the percentage for the same time difference zone of thetime difference specified in S24 (S25). A example of the recovery timeinformation 134 is described below.

[Example of Recovery Time Information]

FIG. 21C is a diagram explaining a example of the recovery timeinformation 134.

The recovery time information 134 illustrated in FIG. 21C includes itemsof “item number” for identifying each information included in therecovery time information 134, “time difference zone” for storing therange of time differences, and “percentage” for storing the percentageof the information stored in “time difference zone” in the wholeinformation.

In the recovery time information 134 illustrated in FIG. 21C, forexample, the information with “item number” of “1” includes “−0:45 to−0:30” stored as “time difference zone” and “5(%)” stored as“percentage”. In the recovery time information 134 illustrated in FIG.21C, the information with “item number” of “2” includes “−0:30 to −0:15”stored as “time difference zone” and “12(%)” stored as “percentage”. Asfor the other information included in FIG. 21C, description thereof isomitted.

Referring back to FIG. 12, the information generation unit 114 specifiesa median value of the time difference zone corresponding to the highestpercentage among the percentage of the information included in therecovery time information 134 generated in S25 (S26). A example of theprocessing in S26 is described below.

[Example of Processing in S26]

FIG. 22C is a diagram explaining a example of the graph illustrating therecovery time information 134.

In the recovery time information 134 illustrated in FIG. 21C, the timedifference zone corresponding to the highest percentage is “0:00 to0:15”. Therefore, in this case, the information generation unit 114specifies 7 minutes 30 seconds, which is the median value between 0minutes and 15 minutes, as the median value of the time difference zonecorresponding to the highest percentage, among the percentageinformation included in the recovery time information 134 generated inS25, as illustrated in FIG. 22C.

Referring to FIG. 13, the information generation unit 114 refers to theinformation storage area 130 storing the fourth history information 131d to specify, for example, a physical resource addition required time inthe past for the physical machine 2 in which the virtual machine 3specified in S13 is operated (S31).

For example, the information generation unit 114 specifies the physicalmachine 2 in which the virtual machine 3 specified in S13 is operated.The information generation unit 114 refers to the informationcorresponding to the specified physical machine 2 and the virtualmachine 3 specified in S13, among the fourth history information 131 d,and specifies the physical resource addition required time in the pastfor the physical machine 2 in which the virtual machine 3 specified inS13 is operated.

The information generation unit 114 generates information indicating thepercentage for the same time zone of the addition required timespecified in S31, as the addition time information 135 (S32). A exampleof the addition time information 135 is described below.

[Example of Addition Time Information]

FIG. 21D is a diagram explaining a example of the addition timeinformation 135.

The addition time information 135 illustrated in FIG. 21D includes itemsof “item number” for identifying each information included in theaddition time information 135, “addition required time zone” for storingthe range of addition required times, and “percentage” for storing thepercentage of the information stored in “addition required time zone” inthe whole information.

In the addition time information 135 illustrated in FIG. 21D, forexample, the information with “item number” of “1” includes “0:00 to0:05” stored as “addition required time zone” and “2(%)” stored as“percentage”. In the addition time information 135 illustrated in FIG.21D, for example, the information with “item number” of “2” includes“0:05 to 0:10” stored as “addition required time zone” and “15(%)”stored as “percentage”. As for the other information included in FIG.21D, description thereof is omitted.

Referring back to FIG. 13, the information generation unit 114 specifiesa median value of the time zone corresponding to the highest percentageamong the percentage of the information included in the addition timeinformation 135 generated in S32, as a fourth reference time (S33). Aexample of the processing in S33 is described below.

[Example of Processing in S33]

FIG. 22D is a diagram explaining a example of the graph illustrating theaddition time information 135.

In the addition time information 135 illustrated in FIG. 21D, the timezone corresponding to the highest percentage (addition required timezone) is “0:10 to 0:15”. Therefore, in this case, the informationgeneration unit 114 specifies 12 minutes 30 seconds, which is the medianvalue between 10 minutes and 15 minutes, as the fourth reference time,as illustrated in FIG. 22D.

Referring back to FIG. 13, the information generation unit 114calculates an elapsed time from the previous operation start time forthe virtual machine 3 specified in S13 to the current time (S34). Theinformation generation unit 114 generates post-conversion operationinterval information 132 a from the operation interval information 132generated in S15, by subtracting the elapsed time calculated in S34 fromeach time interval included in the operation interval information 132generated in S15 (S35).

For example, while the origin of the horizontal axis of the graphrepresenting the movement time information 133 illustrated in FIG. 22Bcorresponds to the current time, the origin of the horizontal axis ofthe graph representing the operation interval information 132illustrated in FIG. 22A corresponds to the previous operation start timefor the virtual machine 3 specified in S13. Therefore, the informationgeneration unit 114 generates the post-conversion operation intervalinformation 132 a in which the origin of the horizontal axis of thegraph representing the operation interval information 132 corresponds tothe current time. Thus, the information processor 1 may compare thegraph representing the post-conversion operation interval information132 a with the graph representing the movement time information 133, andthe like. A example of the post-conversion operation intervalinformation 132 a generated in S35 is described below.

[Example of Post-Conversion Operation Interval Information]

FIG. 23 is a diagram explaining a example of the post-conversionoperation interval information 132 a. FIG. 24 is a diagram explaining aexample of a graph illustrating the post-conversion operation intervalinformation 132 a.

The post-conversion operation interval information 132 a illustrated inFIG. 23 includes items of “item number” for identifying each informationincluded in the post-conversion operation interval information 132 a,“operation start required time zone” for storing time before the nextoperation start time, and “percentage” for storing the percentage of theinformation stored in “operation start required time zone” in the wholeinformation.

For example, when the elapsed time calculated in S34 is 1 hour, theinformation generation unit 114 stores, in “operation start requiredtime zone”, time obtained by subtracting “1:00” from the time stored in“time interval zone” in the operation interval information 132 describedwith reference to FIG. 21A, as illustrated in FIG. 24.

Therefore, in this case, the graph representing the post-conversionoperation interval information 132 a has the same shape as that of thegraph described with reference to FIG. 22A, as illustrated in FIG. 24.In the graph representing the post-conversion operation intervalinformation 132 a, 2 hours 22 minutes 30 seconds is the timecorresponding to the highest percentage, which is obtained bysubtracting 1 hour from 3 hours 22 minutes 30 seconds that is the timecorresponding to the highest percentage in the graph described withreference to FIG. 22A, as illustrated in FIG. 24.

Referring back to FIG. 13, the information generation unit 114 specifiesa median value of the time zone corresponding to the highest percentageamong the times included in the post-conversion operation intervalinformation 132 a generated in S35, as a first reference time (S36).

For example, the information generation unit 114 specifies 2 hours 22minutes 30 seconds as the first reference time, which is the medianvalue between 2 hours 15 minutes and 2 hours 30 minutes as the time zonecorresponding to the highest percentage, among the percentageinformation included in the post-conversion operation intervalinformation 132 a generated in S35, as illustrated in FIG. 23.

As illustrated in FIG. 14, the information generation unit 114determines whether or not the predicted time (hereinafter also referredto as the third reference time) for the recovery required time of thefailure detected to have occurred in S11 is inputted (S41).

As a result, when it is determined that the input of the third referencetime is not detected (NO in S41), the information generation unit 114waits until the input of the third reference time is detected.

When the input of the third reference time is detected (YES in S41), theinformation generation unit 114 generates post-conversion recovery timeinformation 134 a from the recovery time information 134 generated inS25 by allowing the time difference specified in S26 to correspond tothe third reference time detected to be inputted in S41 (S42).

For example, the information generation unit 114 generates thepost-conversion recovery time information 134 a from the recovery timeinformation 134 so as to enable comparison with the graph representingthe movement time information 133, and the like. A example of thepost-conversion recovery time information 134 a generated in S42 isdescribed below.

[Example of Post-Conversion Recovery Time Information]

FIG. 25 is a diagram explaining a example of the post-conversionrecovery time information 134 a. FIG. 26 is a diagram explaining aexample of a graph illustrating the post-conversion recovery timeinformation 134 a.

The post-conversion recovery time information 134 a illustrated in FIG.25 includes items of “item number” for identifying each informationincluded in the post-conversion recovery time information 134 a,“recovery required time” for storing recovery required time, and“percentage” for storing the percentage of the information stored in“recovery required time” in the whole information.

For example, when the third reference time detected to be inputted inS41 is 1 hour 30 minutes, the information generation unit 114 stores, in“recovery required time”, time obtained by adding “1:30” to the timestored in “time difference zone” in the recovery time information 134described with reference to FIG. 21C, as illustrated in FIG. 26.

Therefore, in this case, the graph representing the post-conversionrecovery time information 134 a has the same shape as that of the graphdescribed with reference to FIG. 22C, as illustrated in FIG. 26. In thegraph representing the post-conversion recovery time information 134 a,in this case, 1 hour 37 minutes 30 seconds is the time corresponding tothe highest percentage, which is obtained by adding 1 hour 30 minutes to7 minutes 30 seconds that is the time corresponding to the highestpercentage in the graph described with reference to FIG. 22C, asillustrated in FIG. 26.

Referring back to FIG. 14, the information generation unit 114 comparesthe first reference time specified in S36 with the third reference timedetected to be inputted in S41 (S43).

As a result, when it is determined that the first reference time islarger than the third reference time (YES in S43), the informationgeneration unit 114 calculates, from the post-conversion operationinterval information 132 a generated in S35 and the post-conversionrecovery time information 134 a generated in S42, a first probability atwhich the time before the next operation start time for the virtualmachine 3 specified in S13 is shorter than the recovery required time ofthe failure detected to have occurred in S11 (S44).

For example, the information generation unit 114 expresses, on the sameplane, the graph representing the post-conversion operation intervalinformation 132 a generated in S35 (the graph described with referenceto FIG. 24) and the graph representing the post-conversion recovery timeinformation 134 a generated in S42 (the graph described with referenceto FIG. 26) after converting the graphs such that the both graphs havethe same maximum value as illustrated in FIG. 27A, for example. Forexample, the information generation unit 114 calculates, as the firstprobability, the percentage of the area of the overlapping portion(shaded area in FIG. 27A) between the graph representing thepost-conversion operation interval information 132 a and the graphrepresenting the post-conversion recovery time information 134 a, in thearea surrounded by the graph representing the post-conversion operationinterval information 132 a and the horizontal axis.

The movement determination unit 115 in the information processor 1compares the first probability calculated in S44 with a first threshold(for example, a threshold predetermined by the operator) (S45).

For example, the first probability is a probability at which therecovery of the currently occurring failure does not end at the nextoperation start time for the virtual machine 3 specified in S13.Therefore, when the first reference time is larger than the thirdreference time and when the first probability is larger than the firstthreshold, the movement determination unit 115 speculates that therecovery of the currently occurring failure has a high probability ofnot ending at the next operation start time for the virtual machine 3specified in S13. Therefore, the movement determination unit 115determines, in this case, that it is desirable to take measures for thevirtual machine 3 specified in S13, such as movement to the differentphysical machine 2.

The movement determination unit 115 may compare, in S45, the area of theoverlapping portion (shaded area in FIG. 27A) between the graphrepresenting the post-conversion operation interval information 132 aand the graph representing the post-conversion recovery time information134 a with a predetermined threshold, instead of comparing the firstprobability with the first threshold.

When the first probability is larger than the first threshold (YES inS45), the information generation unit 114 compares the first referencetime specified in S36 with the second reference time specified in S23(S46).

The information generation unit 114 performs the processing of S46 alsowhen the first reference time is not larger than the third referencetime (NO in S43).

When the first reference time is not larger than the third referencetime, the movement determination unit 115 speculates that the recoveryof the currently occurring failure has a high probability of not endingat the next operation start time for the virtual machine 3 specified inS13. Therefore, the movement determination unit 115 determines, in thiscase, again, that it is desirable to take measures for the virtualmachine 3 specified in S13, such as movement to the different physicalmachine 2.

When it is determined that the first reference time is larger than thesecond reference time (YES in S46), the information generation unit 114calculates, from the post-conversion operation interval information 132a generated in S35 and the movement time information 133 generated inS22, a second probability at which the time before the next operationstart time for the virtual machine 3 specified in S13 is shorter thanthe movement required time when movement of the virtual machine 3specified in S13 is to be started next, as illustrated in FIG. 15 (S51).

For example, the information generation unit 114 expresses, on the sameplane, the graph representing the post-conversion operation intervalinformation 132 a generated in S35 (the graph described with referenceto FIG. 24) and the graph representing the movement time information 133generated in S22 (the graph described with reference to FIG. 22B) afterconverting the graphs such that the both graphs have the same maximumvalue as illustrated in FIG. 27B. The information generation unit 114calculates, as the second probability, the percentage of the area of theoverlapping portion (shaded area in FIG. 27B) between the graphrepresenting the post-conversion operation interval information 132 aand the graph representing the movement time information 133, in thearea surrounded by the graph representing the post-conversion operationinterval information 132 a and the horizontal axis.

The movement determination unit 115 compares the second probabilitycalculated in S51 with a second threshold (for example, a thresholdpredetermined by the operator) (S52).

The movement determination unit 115 may compare, in S52, the area of theoverlapping portion (shaded area in FIG. 27B) between the graphrepresenting the post-conversion operation interval information 132 aand the graph representing the movement time information 133 with apredetermined threshold, instead of comparing the second probabilitywith the second threshold.

When the second probability is not larger than the second threshold (NOin S52), the information generation unit 114 determines that the virtualmachine 3 specified in S13 is to be moved to the different physicalmachine 2 (S53).

For example, the second probability is a probability at which themovement of the virtual machine 3 specified in S13 does not end at thenext operation start time, when the movement of the virtual machine 3 isto be started next. Therefore, when the second probability is not largerthan the second threshold, the movement determination unit 115speculates that the movement of the virtual machine 3 specified in S13has a low probability of not ending at the next operation start time,when the movement of the virtual machine 3 is to be started next.Therefore, in this case, the movement determination unit 115 determinesto move the virtual machine 3 specified in S13.

On the other hand, when the second probability is larger than the secondthreshold (YES in S52), the information generation unit 114 compares thefirst reference time specified in S36 with the fourth reference timespecified in S33 (S54). The information generation unit 114 performs theprocessing of S54 also when the first reference time is not larger thanthe second reference time (NO in S46).

For example, when the first reference time is larger than the secondreference time and when the second probability is larger than the secondthreshold or when the first reference time is not larger than the secondreference time, the movement determination unit 115 speculates that themovement of the virtual machine 3 specified in S13 has a highprobability of not ending at the next operation start time. Therefore,in this case, the movement determination unit 115 determines whether toadd physical resources to the virtual machine 3 specified in S13,instead of moving the virtual machine 3 specified in S13 to thedifferent physical machine 2.

When the first reference time is larger than the fourth reference time(YES in S54), the movement determination unit 115 determines to addphysical resources to the virtual machine 3 specified in S13 (S55).

On the other hand, when the first reference time is not larger than thefourth reference time (NO in S54), the movement determination unit 115does not perform the processing of S55.

For example, in this case, the movement determination unit 115determines that not only the movement of the virtual machine 3 specifiedin S13 but also the addition of the physical resources to the virtualmachine 3 specified in S13 may not be performed.

When the first reference time is larger than the fourth reference time(YES in S54), the information generation unit 114 may calculate, fromthe post-conversion operation interval information 132 a generated inS35 and the addition time information 135 generated in S32, aprobability (hereinafter also referred to as the third probability) atwhich the time before the next operation start time for the virtualmachine 3 specified in S13 is shorter than the addition required timewhen addition of physical resources to the virtual machine 3 specifiedin S13 is to be started next.

When the third probability is not larger than a third threshold (forexample, a threshold predetermined by the operator), the movementdetermination unit 115 may perform the processing of S55, speculatingthat the addition of physical resources has a low probability of notending at the next operation start time. When the third probability islarger than the third threshold, the movement determination unit 115 maynot perform the processing of S55, speculating that the addition ofphysical resources of the physical machine 2 has a high probability ofnot ending at the next operation start time.

Thereafter, as illustrated in FIG. 16, the movement determination unit115 determines whether or not more than one virtual machine 3 isextracted in S12 (S61).

As a result, when only one virtual machine 3 is extracted in S12 (NO inS61), the information processor 1 terminates the VM movementdetermination processing.

On the other hand, when more than one virtual machine 3 is extracted inS12 (YES in S61), the movement determination unit 115 determines whetheror not the processing of S53 is performed for the virtual machines 3extracted in S12 (S62).

When it is determined that the processing of S53 is performed (YES inS62), the movement determination unit 115 calculates priorityinformation 137 indicating the priority of the virtual machine 3specified in S13, from the second probability calculated in S51 andimportance information 136 indicating the importance of the virtualmachine 3 specified in S13 (S63).

For example, the movement determination unit 115 may calculate thepriority information 137 of the virtual machine 3 specified in S13 bymultiplying the second probability calculated in S51 by the valueindicated by the importance information 136 on the virtual machine 3specified in S13.

The importance information 136 is information predetermined by theoperator, which may be, for example, information determined according touser receiving services by executing the virtual machine 3 specified inS13. Alternatively, the importance information 136 may be determined,for example, according to spending, business type, or the like of theuser receiving services. Alternatively, the importance information 136may be determined according to the number of applications run in thevirtual machine 3 specified in S13, or the like.

On the other hand, when it is determined that the processing of S53 isnot performed (NO in S62), the movement determination unit 115 does notperform the processing of S63.

The information generation unit 114 determines whether or not everyvirtual machine 3 extracted in S12 has been specified in S13 (S64).

As a result, when it is determined that not every virtual machine 3 hasbeen specified (NO in S64), the information processor 1 performs againthe processing from S13.

On the other hand, when it is determined that every virtual machine 3has been specified (YES in S64), the movement determination unit 115groups the virtual machines 3 extracted in S12 by the physical machine 2in which the respective virtual machines 3 are operated (S65).

The movement determination unit 115 performs processing of determiningthe order of handling the virtual machines 3 extracted in S12(hereinafter also referred to as the handling order determinationprocessing) for each group of the virtual machines 3 grouped in S64(S66).

For example, the information processor 1 may simultaneously perform thehandling of the virtual machines 3 grouped into different groups in S64(virtual machines 3 operated in different physical machines 2).Therefore, the movement determination unit 115 performs the handlingorder determination processing for each of the virtual machines 3grouped in S64.

The information processor 1 terminates the VM movement determinationprocessing. Hereinafter, description is given of a example of theimportance information 136 and the priority information 137 when it isdetermined that every virtual machine 3 has been specified in S64.

Example (1) of Importance Information and Priority Information

FIGS. 28 and 29 are diagrams explaining examples of the importanceinformation 136 and the priority information 137.

The information illustrated in FIG. 28 and the like includes items of“item number” for identifying each information, “virtual machine” forstoring identification information of each virtual machine 3, “handling”for storing contents of handling determined in S53 or S55, and “secondprobability” for storing the second probability calculated in S51. In“handling”, “movement” determined in S53 or “addition of physicalresources” determined in S55 is stored. The information illustrated inFIG. 28 and the like also includes items of “importance” for storing theimportance information 136, “priority” for storing the priorityinformation 137, and “physical machine” for storing identificationinformation of the physical machine 2 in which the respective virtualmachines 3 are operated. When “addition of physical resources” is storedin “handling”, “-” is stored in “second probability” and “priority”,indicating that no information is stored.

For example, in the information illustrated in FIG. 28, the informationwith “item number” of “1” includes “VM1” stored as “virtual machine”,“movement” stored as “handling”, “0.4” stored as “second probability”,“1” stored as “importance”, “0.4” stored as “priority”, and “A” storedas “physical machine”.

Also, in the information illustrated in FIG. 28, the information with“item number” of “3” includes “VM3” stored as “virtual machine”,“physical resources added” stored as “handling”, “-” stored as “secondprobability”, “3” stored as “importance”, “-” stored as “priority”, and“A” stored as “physical machine”. As for the other information includedin FIG. 28, description thereof is omitted.

[Handling Order Determination Processing (1)]

Next, description is given of a example of the handling orderdetermination processing. FIG. 17 is a flowchart explaining a example ofthe handling order determination processing with reference to FIGS. 1-3and 5. Hereinafter, description is given of the handling orderdetermination processing for the virtual machines 3 included in a groupcorresponding to one physical machine 2.

As illustrated in FIG. 17, the movement determination unit 115 specifiesa virtual machine 3 having the highest value of the priority information137 calculated in S63, among the virtual machines 3 extracted in S12(S71).

For example, the movement determination unit 115 refers to theinformation described with reference to FIG. 28, for example, to specify“VM2” stored as “virtual machine” in the information with “0.6” storedas “priority”.

When the virtual machine 3 determined to be moved to the differentphysical machine 2 (virtual machine 3 subjected to the processing ofS53) is not present in the virtual machines 3 extracted in S12, themovement determination unit 115 may specify the virtual machine 3 havingthe highest value indicated by the importance information 136 stored inthe information storage area 130, among the virtual machines 3determined to have physical resources added thereto (virtual machines 3subjected to the processing of S55).

The movement determination unit 115 refers to the priority information137 calculated in S63 (priority information 137 calculated in theprocessing of S75 performed last when the priority information 137 iscalculated in S75) to perform handling of the virtual machine 3specified in S71 (S72).

For example, the movement determination unit 115 refers to the priorityinformation 137 calculated in S63 or the like to perform handling inwhich the information indicating the virtual machine 3 specified in S71corresponds to the contents set as “handling” in the information set in“virtual machine”.

In this case, for example, the movement determination unit 115 mayspontaneously move the virtual machine 3 specified in S71 or addphysical resources to the virtual machine 3 specified in S71.

Alternatively, the movement determination unit 115 may output, forexample, an instruction to move the virtual machine 3 specified in S71or to add physical resources to the virtual machine 3 specified in S71to an output screen (not illustrated) of the operation terminal 5. Theoperator may view the output screen of the operation terminal 5, forexample, to move the virtual machine 3 specified in S71 or to addphysical resources to the virtual machine 3 specified in S71.

The movement determination unit 115 waits until the handling of thevirtual machine 3 specified in S71 is completed (NO in S73).

When the handling of the virtual machine 3 specified in S71 is completed(YES in S73), the movement determination unit 115 determines whether ornot handling of all the virtual machines 3 extracted in S12 is completed(S74).

As a result, when it is determined that the handling of all the virtualmachines 3 is completed (YES in S74), the information processor 1terminates the handling order determination processing.

On the other hand, when it is determined that the handling of all thevirtual machines 3 is not completed (NO in S74), the movementdetermination unit 115 calculates again the priority information 137 foreach of the virtual machines 3 yet to be handled, among the virtualmachines 3 extracted in S12 (S75). The movement determination unit 115performs again the processing from S71.

For example, when movement of the virtual machine 3 specified in S71 isperformed, the number of the virtual machines 3 operated in eachphysical machine 2 is changed. When the post-conversion operationinterval information 132 a is generated again, time obtained bysubtracting the time required for the handling of the virtual machine 3specified in S71 from the operation start required time included in thepost-conversion operation interval information 132 a described withreference to FIG. 23 is stored as the operation start required timeincluded in the post-conversion operation interval information 132 agenerated again.

Therefore, the movement determination unit 115 calculates again thepriority information 137 corresponding to a situation after the handlingof the virtual machine 3 specified in S71 is performed, for each of thevirtual machines 3 yet to be handled among the virtual machines 3extracted in S12. For example, the movement determination unit 115calculates again the priority information 137 by performing again theprocessing from S13 to S64 by referring to the history information 131(the first history information 131 a, the second history information 131b, the third history information 131 c, and the fourth historyinformation 131 d) corresponding to the current situation (each virtualmachine 3 and the number of the virtual machines 3 operated in the samephysical machine 2) for each of the virtual machines 3 yet to be movedamong the virtual machines 3 extracted in S12 after the movement of thevirtual machine 3 specified in S71 is performed. The movementdetermination unit 115 specifies a virtual machine 3 to be handled nextby referring to the priority information 137 calculated again.

Thus, the information processor 1 may quickly perform handling of eachvirtual machine 3 while suppressing the influence of a failure that hasoccurred on services. The movement determination unit 115 may accuratelysuppress occurrence of failure in the virtual machine 3 that does notoperate until next operation start time.

When the priority information 137 is calculated again, it may bedetermined, for example, that there have been no changes in theoperation interval information 132 described with reference to FIG. 21Aand the recovery time information 134 described with reference to FIG.21C since the previous calculation of the priority information 137.Therefore, when calculating again the priority information 137, theinformation processor 1 may use the results obtained when the processingof S16 and S26 is previously performed, without performing theprocessing of S14 to S16 and S24 to S26.

For example, when no virtual machine 3 is moved in the processing of S72previously performed, it may be determined that there has been no changein the movement time information 133 described with reference to FIG.21B since the previous calculation of the priority information 137.Therefore, the information processor 1 may use the result obtained whenthe processing of S23 is previously performed, without performing theprocessing of S21 to S23.

For example, when no physical resources are added in the processing ofS72 previously performed, it may be determined that there has been nochange in the addition time information 135 described with reference toFIG. 21D since the previous calculation of the priority information 137.Therefore, in this case, the information processor 1 may use the resultobtained when the processing of S33 is previously performed, withoutperforming the processing of S31 to S33. Hereinafter, description isgiven of a example of the importance information 136 and the priorityinformation 137 after the priority information 137 is calculated again.

Example (2) of Importance Information and Priority Information

FIG. 29 is a diagram explaining a example of the importance information136 and the priority information 137 after the priority information 137is calculated again.

For example, in the information illustrated in FIG. 29, the informationwith “item number” of “1” includes “VM1” stored as “virtual machine”,“movement” stored as “handling”, “0.4” stored as “second probability”,“1” stored as “importance”, “0.4” stored as “priority”, and “A” storedas “physical machine”, as in the case of FIG. 28.

Meanwhile, in the information illustrated in FIG. 29, the informationwith “item number” of “3” includes “VM3” stored as “virtual machine”,“movement” stored as “handling”, “0.4” stored as “second probability”,“3” stored as “importance”, “1.2” stored as “priority”, and “A” storedas “physical machine”, unlike the case of FIG. 28.

For example, the example illustrated in FIG. 29 represents the casewhere the contents of handling of the virtual machine 3 with theidentification information of “VM3” are changed from the addition ofphysical resources to the movement of the virtual machine 3, as a resultof the movement of the virtual machine 3 with the identificationinformation of “VM2” (the virtual machine 3 specified in S71).

In the processing of S71 and S72, the movement determination unit 115may perform the handling sequentially from the virtual machine 3 withhigh priority information 137 calculated in S63. For example, themovement determination unit 115 may determine the order of the virtualmachines 3 to be handled based on the contents of the priorityinformation 137 first calculated, without repeating the calculation ofthe priority information 137 (processing of S75).

[Handling Order Determination Processing (2)]

Next, description is given of another example of the handling orderdetermination processing. FIGS. 18 and 19 are flowcharts explaininganother example of the handling order determination processing withreference to FIGS. 1-3 and 5. Hereinafter, description is given of thehandling order determination processing for the virtual machines 3included in a group corresponding to one physical machine 2.

In another example of the handling order determination processing, themovement determination unit 115 previously estimates handling that maybe performed for each virtual machine 3 when following the handlingorder for the virtual machine 3, unlike the handling order determinationprocessing described with reference to FIG. 17. The movementdetermination unit 115 specifies an optimum solution (for example, thehandling order that enables movement of the largest number of virtualmachines 3) from the estimated handling order, and performs handling ofeach virtual machine 3 according to the specified handling order. Thisanother example of the handling order determination processing isdescribed in detail below.

As illustrated in FIG. 18, the movement determination unit 115 specifiesone virtual machine 3 from among those in the handling order, which areextracted in S12 (S81).

For example, the movement determination unit 115 specifies the handlingorder, for example, in which the virtual machine 3 with theidentification information of “VM1” comes first, the virtual machine 3with the identification information of “VM2” comes second, and thevirtual machine 3 with the identification information of “VM3” comesthird.

The movement determination unit 115 specifies the virtual machine 3assumed to be handled in S53 or S55, of which actual handling is yet tobe determined in S84, among the virtual machines 3 included in thehandling order specified in S81 (S82).

For example, when there is no virtual machine 3 assumed to be handled inS53 or S55, of which actual handling is determined in S84, the movementdetermination unit 115 specifies all of the virtual machine 3 with theidentification information of “VM1”, the virtual machine 3 with theidentification information of “VM2”, and the virtual machine 3 with theidentification information of “VM3”.

The movement determination unit 115 specifies the virtual machine 3 tobe determined to be handled next, from among the virtual machines 3specified in S82 (S83).

For example, when the virtual machine 3 with the identificationinformation of “VM1”, the virtual machine 3 with the identificationinformation of “VM2”, and the virtual machine 3 with the identificationinformation of “VM3” are specified in S82, the movement determinationunit 115 specifies the virtual machine 3 with the identificationinformation of “VM1” (the virtual machine 3 that comes first in thehandling order).

The movement determination unit 115 refers to the priority information137 calculated in S63 (when the priority information 137 is calculatedin S75, the priority information 137 calculated in the processing lastperformed in S75) to determine handling of the virtual machine 3specified in S83 (S84).

For example, in the information described with reference to FIG. 28, theinformation with “virtual machine” of “VM1” (information with “itemnumber” of “1”) includes “movement” stored as “handling”. Therefore, inthis case, as the handling of the virtual machine 3 with theidentification information of “VM1”, the movement determination unit 115determines to move the virtual machine 3 to the different physicalmachine 2.

The movement determination unit 115 calculates again the priorityinformation 137 for the virtual machine 3 assumed to be handled in S53or S55, of which actual handling is yet to be determined in S84, amongthe virtual machines 3 included in the handling order specified in S81(S85).

For example, in this case, the movement determination unit 115calculates again the priority information 137 by calculating again theprocessing from S13 to S64, as in the case of the processing describedin S75.

For example, when handling of the virtual machine 3 with theidentification information of “VM1” is determined in S84, for example,the priority information 137 after moving the virtual machine 3 with theidentification information of “VM1” is moved to the different physicalmachine 2 is calculated for the virtual machine 3 with theidentification information of “VM2” and the virtual machine 3 with theidentification information of “VM3”, respectively.

The movement determination unit 115 determines whether or not actualhandling is determined for all the virtual machines 3 included in thehandling order specified in S81 (S86).

As a result, when it is determined that actual handling is notdetermined for all the virtual machines 3 included in the handling orderspecified in S81 (NO in S86), the movement determination unit 115performs again the processing from S82.

On the other hand, when it is determined that actual handling isdetermined for all the virtual machines 3 included in the handling orderspecified in S81 (YES in S86), the movement determination unit 115determines whether or not the handling order is specified in S81 forevery handling order of the virtual machines 3 extracted in S12, asillustrated in FIG. 19 (S91).

When it is determined that the handling order is not specified for everyhandling order of the virtual machines 3 extracted in S12 (NO in S91),the movement determination unit 115 performs again the processing fromS81.

On the other hand, when it is determined that the handling order isspecified for every handling order of the virtual machines 3 extractedin S12 (YES in S91), the movement determination unit 115 calculates thenumber of the virtual machines 3 that may be moved to the differentphysical machine 2, for each order of the virtual machines 3 extractedin S12, for example (S92).

The movement determination unit 115 performs handling of the virtualmachine 3 extracted in S12 according to the handling order with thelargest number calculated in S92, for example (S93).

For example, the movement determination unit 115 performs, for eachvirtual machine 3, the handling determined in S84 for the handling orderwith the largest number calculated in S92.

For example, for each possible handling order for each virtual machine3, the movement determination unit 115 estimates the contents of thehandling that may be performed for each virtual machine 3 withoutactually performing the handling of each virtual machine 3. The movementdetermination unit 115 specifies the handling order that may satisfy apredetermined condition (for example, the handling order with thelargest number of the virtual machines 3 that may be moved to thedifferent physical machine 2) among the possible handling orders foreach virtual machine 3. The movement determination unit 115 performs thehandling of each virtual machine 3 according to the specified handlingorder.

Thus, the information processor 1 may perform flexible handling of eachvirtual machine 3 according to the occurrence of failure and the like.The movement determination unit 115 may accurately suppress theoccurrence of failure in the virtual machine 3 not operated until thenext operation start time, as in the case of the handling orderdetermination processing described with reference to FIG. 17.

For example, the movement determination unit 115 may calculate thenumber of virtual machines 3 for which both of the movement to thedifferent physical machine 2 and the addition of physical resources ofthe physical machine 2 may not be performed. The movement determinationunit 115 may perform the handling determined in S53 or S55, for each ofthe virtual machines 3 extracted in S12, according to the handling orderwith the smallest number of virtual machines 3 for which both of themovement to the different physical machine 2 and the addition ofphysical resources of the physical machine 2 may not be performed.

Alternatively, the movement determination unit 115 may perform thehandling determined in S53 or S55, for each of the virtual machines 3extracted in S12, according to the handling order with the smallestfirst probability for the virtual machine 3 having the highest valueindicated by the importance information 136, among the virtual machines3 extracted in S12.

Thus, the information processor 1 according to this embodiment extractsthe virtual machine 3 before starting its operation from among thevirtual machines 3 within the range of influence of a failure detectedto have occurred upon detection of the occurrence of the failure. Theinformation processor 1 refers to the information storage area 130storing the history information 131 to generate the operation intervalinformation 132 for the extracted virtual machine 3, the movement timeinformation 133 for the extracted virtual machine 3, and the recoverytime information 134 for the failure detected to have occurred.

The information processor 1 determines whether to move the extractedvirtual machine 3 to the different physical machine 2, based on thegenerated operation interval information 132, movement time information133, and recovery time information 134.

For example, the information processor 1 refers to the historyinformation 131 that is the information about failures that haveoccurred in the past or the information about operating conditions ofthe virtual machine 3, and predicts the time when the extracted virtualmachine 3 starts its next operation, the time required when theextracted virtual machine 3 is to be moved next, and the time requiredfor recovery of the failure detected to have occurred. The informationprocessor 1 specifies the virtual machine 3 that may be moved to thedifferent physical machine 2 before the next operation is started, basedon the predicted various information. The information processor 1further determines the specified virtual machine 3 as the virtualmachine 3 to be moved to the different physical machine 2.

Accordingly, the information processor 1 may properly determine thevirtual machine 3 required to be moved to the different physical machine2 in the event of failure. Thus, the operator may further suppress theinfluence of the failure that has occurred.

When performing the handling for each of the virtual machines 3extracted in S12, the information processor 1 may, for example, performhandling of the virtual machine 3 determined to be moved to thedifferent physical machine 2 before handling of the virtual machine 3determined to have physical resources added thereto.

In the case of performing the VM movement determination processing, whenthere is no history information 131 corresponding to the virtual machine3 extracted in S12 and the physical machine 2 in which the virtualmachine 3 extracted in S12 is operated, the information processor 1 mayperform subsequent processing by referring to the existing information(for example, the history information 131 with similar conditions). Forexample, when there is the history information 131 corresponding to thevirtual machine 3 extracted in S12 but there is no history information131 corresponding to the virtual machine 3 extracted in S12 and thephysical machine 2 in which the virtual machine 3 extracted in S12 isoperated, the information processor 1 may perform subsequent processingby referring to the history information 131 corresponding to the virtualmachine 3 extracted in S12.

When there is no history information 131 corresponding to the virtualmachine 3 extracted in S12 and the physical machine 2 in which thevirtual machine 3 extracted in S12 is operated, the informationprocessor 1 may notify the operator to that effect. The informationprocessor 1 may perform subsequent processing, for example, by referringto the history information 131 selected by the operator among thegenerated history information 131.

When the history information 131 is generated according to the number ofthe virtual machines 3 operated in the physical machine 2, for example,if there is no history information 131 corresponding to the number ofthe virtual machines 3 operated in the same physical machine 2 as thatof the virtual machine 3 extracted in S12, the information processor 1may calculate the percentage of the number of the virtual machines 3operated in the same physical machine 2 as that of the virtual machine 3extracted in S12 (hereinafter also referred to as the number percentage)among all the virtual machines 3 operated in the information processingsystem 10. The information processor 1 may perform subsequent processingby referring to the history information 131 corresponding to the numberpercentage close to the calculated number percentage, among thegenerated history information 131.

Thus, the information processor 1 may properly perform the VM movementdetermination processing even when no history information 131 isgenerated that meets the conditions.

All examples and conditional language provided herein are intended forthe pedagogical purposes of aiding the reader in understanding theinvention and the concepts contributed by the inventor to further theart, and are not to be construed as limitations to such specificallyrecited examples and conditions, nor does the organization of suchexamples in the specification relate to a showing of the superiority andinferiority of the invention. Although one or more embodiments of thepresent invention have been described in detail, it should be understoodthat the various changes, substitutions, and alterations could be madehereto without departing from the spirit and scope of the invention.

What is claimed is:
 1. A non-transitory, computer-readable recordingmedium having stored therein a program for causing a computer to executea process comprising: extracting a virtual machine before startingoperation from among virtual machines within a range of influence of afailure upon detection of the failure; with reference to a memory forstoring history information concerning operation of the virtual machine,generating first information corresponding to time intervals ofoperation start time of the extracted virtual machine, secondinformation corresponding to movement required time required to move theextracted virtual machine out of the range of influence of the failure,and third information corresponding to recovery required time requiredfor recovery of the failure detected to have occurred; and determiningwhether to move the extracted virtual machine out of the range ofinfluence of the failure, based on the generated first, second, andthird information.
 2. The non-transitory, computer-readable recordingmedium of claim 1, wherein the generating includes: referring to thememory for storing the history information to specify one or more timeintervals in the past for the extracted virtual machine, generating, asthe first information, information indicating a percentage for each ofthe specified time intervals to whole the specified time intervals,referring to the memory for storing the history information to specifymovement required times in the past for the extracted virtual machine,generating, as the second information, information indicating thepercentage for each of the specified movement required times to wholethe specified movement required times, referring to the memory forstoring the history information to calculate a time difference betweenthe recovery required time upon a past occurrence of the failure and apredicted time for the recovery required time predicted upon the pastoccurrence of the failure, for each of failures occurred in the past,and generating, as the third information, information indicating apercentage for each of the calculated time differences to whole thecalculated time differences.
 3. The non-transitory, computer-readablerecording medium of claim 2, wherein the determining includes:calculating an elapsed time from a previous operation start time to acurrent time for the extracted virtual machine, calculating, from thefirst and third information, a first probability at which a timeobtained by subtracting the calculated elapsed time from a selected oneof the time intervals is shorter than a time obtained by adding thecalculated time difference to the predicted time for the recoveryrequired time predicted for the failure detected to have occurred,calculating, from the first and second information, when the calculatedfirst probability is not less than a first threshold, a secondprobability at which the time obtained by subtracting the calculatedelapsed time from the selected one of the time intervals is shorter thanthe movement required time, and moving, when the calculated secondprobability is not more than a second threshold, the extracted virtualmachine out of the range of influence of the failure.
 4. Thenon-transitory, computer-readable recording medium of claim 2, whereinthe generating includes generating the first information, the secondinformation, and the third information for each of the virtual machineswhen there is more than one virtual machine extracted; and thedetermining includes: calculating, when there is more than one virtualmachine determined to be moved out of the range of influence of thefailure, priority information for each of the virtual machines from thefirst probability, and determining to move the virtual machines out ofthe range of influence of the failure sequentially from a virtualmachine having a larger value of the priority information calculated. 5.The non-transitory, computer-readable recording medium of claim 4, theprocess further comprising when a plurality of virtual machines beforeoperation have been extracted, performing again the determining ofwhether to move the extracted virtual machines out of the range ofinfluence of the failure, upon completion of the movement of each of theplurality of virtual machines out of the range of influence of thefailure.
 6. The non-transitory, computer-readable recording medium ofclaim 4, the process further comprising: when a plurality of virtualmachines before operation have been extracted, calculating the number ofthe virtual machines that may be moved out of the range of influence ofthe failure when moving more than one virtual machine in a predeterminedorder by repeating the determining of whether to move the extractedvirtual machines out of the range of influence of the failure, whileassuming that the plurality of virtual machines are moved one by one inthe predetermined order; and determining to move more than one virtualmachine in the predetermined order when the calculated number is notless than a threshold.
 7. The non-transitory, computer-readablerecording medium of claim 1, wherein: the generating includes referringto the memory for storing the history information to generate fourthinformation indicating addition required time required to add resourcesof a physical machine in which the extracted virtual machine isoperated; and the determining includes determining, based on thegenerated first and fourth information, whether to add the resources ofthe physical machine in which the extracted virtual machine is operated,when determining that the extracted virtual machine is not to be movedout of the range of influence of the failure.
 8. The non-transitory,computer-readable recording medium of claim 1, wherein the generatingthe first information, the second information, and the third informationincludes: specifying a physical machine in which the extracted virtualmachine is operated, specifying the number of virtual machines operatedin the specified physical machine, and referring to the memory forstoring history information to specify history information correspondingto the specified number, among the history information, to generate thefirst information, the second information, and the third information. 9.A failure handling method performed by a processor included in a failurehandling apparatus, the failure handling method comprising: extracting avirtual machine before starting operation from among virtual machineswithin a range of influence of a failure upon detection of the failure;referring to a memory for storing history information concerningoperation of a virtual machine to generate first informationcorresponding to time intervals of operation start time of the extractedvirtual machine, second information corresponding to movement requiredtime required to move the extracted virtual machine out of the range ofinfluence of the failure, and third information corresponding torecovery required time required for recovery of the failure detected tohave occurred; and determining whether to move the extracted virtualmachine out of the range of influence of the failure, based on thegenerated first, second, and third information.
 10. The failure handlingmethod of claim 9, wherein the generating includes: referring to thememory for storing the history information to specify a time interval inthe past for the extracted virtual machine; generating, as the firstinformation, information indicating a percentage for each of thespecified time intervals to whole the specified time intervals;referring to the memory for storing the history information to specifymovement required times in the past for the extracted virtual machine;generating, as the second information, information indicating thepercentage for each of the specified movement required times to wholethe specified movement required times; referring to the memory forstoring the history information to calculate a time difference betweenthe recovery required time upon a past occurrence of the failure and apredicted time for the recovery required time predicted upon the pastoccurrence of the failure, for each of failures occurred in the past;and generating, as the third information, information indicating apercentage for each of the calculated time differences to whole thecalculated time differences.
 11. The failure handling method of claim 9,wherein the determining includes: calculating an elapsed time from aprevious operation start time to a current time for the extractedvirtual machine, calculating, from the first and third information, afirst probability at which a time obtained by subtracting the calculatedelapsed time from a selected one of the time intervals is shorter than atime obtained by adding the calculated time difference to the predictedtime for the recovery required time predicted for the failure detectedto have occurred, calculating, from the first and second information,when the calculated first probability is not less than a firstthreshold, a second probability at which the time obtained bysubtracting the calculated elapsed time from the selected one of thetime intervals is shorter than the movement required time, and moving,when the calculated second probability is not more than a secondthreshold, the extracted virtual machine out of the range of influenceof the failure.
 12. A failure handling method comprising: determining aplurality of physical machines that are connected to a network;determining a plurality of virtual machines running on the plurality ofphysical machines; determining an operation status of the plurality ofvirtual machines, the operation status comprising an in-operation statusor a not-in-operation status; determining whether a failure has occurredin a virtual machine; determining a range of influence of the failure;determining a not-in-operation virtual machine having a not-in-operationstatus and a location within the range of influence; determining whetherto move the not-in-operation virtual machine; and moving thenot-in-operation virtual machine to a location outside the range ofinfluence when a determination is made to move the not-in-operationvirtual machine, the determining the plurality of virtual machinescomprises accessing history information stored in a storage area of aninformation processor, and the history information comprises any ofoperation start time, movement time, and recovery time.
 13. The methodof claim 12 further comprising extracting the not-in-operation virtualmachine.
 14. The method of claim 13 further comprising generating any ofinformation corresponding to time intervals of the operation start timeof an extracted virtual machine, the movement time, and the recoverytime.
 15. The method of claim 14, wherein the determining whether tomove the not-in-operation virtual machine is based on any of theinformation generated.